1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor, and specifically, to a multilayer ceramic capacitor including a structure that includes a ceramic body and outer electrodes, the ceramic body including inner electrodes, and the outer electrodes being electrically connected to the inner electrodes.
2. Description of the Related Art
An example of typical electronic ceramic components is a multilayer ceramic capacitor as disclosed in Japanese Unexamined Patent Application No. 2006-213946.
As illustrated in FIG. 10, the structure of the multilayer ceramic capacitor includes a ceramic multilayer body (ceramic body) 110 and a pair of outer electrodes 104 (104a, 104b) arranged on a pair of end surfaces 103 (103a, 103b), respectively, of the ceramic multilayer body 110, the ceramic multilayer body 110 including a plurality of inner electrodes 102 (102a, 102b) stacked alternately with ceramic layers 101 serving as dielectric layers, and the outer electrodes 104 (104a, 104b) being electrically connected to the inner electrodes 102 (102a, 102b).
The outer electrodes 104 (104a, 104b) include sintered metal layers 105 (105a, 105b) arranged to extend from the end surfaces 103 of the ceramic multilayer body 110 to main surfaces and side surfaces of the ceramic multilayer body 110; and plating layers 106 (106a, 106b) arranged to cover surfaces of the sintered metal layers 105, the sintered metal layers 105 being formed by, for example, baking a conductive paste containing a Cu powder serving as a conductive component.
The plating layers 106 (106a, 106b) include Ni plating layers 107 (107a, 107b) arranged on surfaces of the sintered metal layers 105 (105a, 105b); and Sn plating layers 108 (108a, 108b) arranged on the Ni plating layers 107 (107a, 107b).
The multilayer ceramic capacitor having the foregoing structure has portions where the inner electrodes are not present. The portions are between end portions of the inner electrodes in the width direction, which is a direction perpendicular or substantially perpendicular to both the direction in which the inner electrodes extend and the direction in which the inner electrodes are stacked, and the side surfaces of the ceramic body. In the portions, steps are formed between portions where the inner electrodes are not present and portions where the inner electrodes are present.
The steps cause the positional deviations of the inner electrodes in a stacking step and a pressure-bonding step when the multilayer ceramic capacitor is manufactured.
A multilayer ceramic capacitor is often produced by the steps of stacking mother ceramic green sheets to form a mother multilayer body, the steps of pressure-bonding the resulting mother multilayer body, and the steps of dividing the pressed mother multilayer body into individual elements. In the case of producing a multilayer ceramic capacitor by such a method, if the positional deviation occurs in the stacking step and the pressure-bonding step, the following problems arise: a reduction in the area of an effective region in which adjacent inner electrodes in the stacking direction overlap each other and which contributes to capacitance generation; and the impairment of the mounting stability of the multilayer ceramic capacitor because of a failure to accurately produce a ceramic body having a substantially rectangular parallelepiped shape.
In recent years, a trend toward higher capacitance of multilayer ceramic capacitors has required the stacking of larger number of inner electrodes. The stacking of a large number of inner electrodes may reduce the distance between inner electrodes and surfaces of ceramic bodies, causing a fatal problem of a reduction in moisture resistance reliability.